1. Field of the Invention
The present invention relates to a pixel structure of a display panel and method of making the same, and more particularly, to a pixel structure including two storage capacitors composed of three layers of overlapping electrodes and method of making the same.
2. Description of the Prior Art
A pixel structure of a liquid crystal display (LCD) requires a storage capacitor, which can increase the storage capacitance so that electrical charges injected into the pixel electrode can be sustained until next scanning. Please refer to FIG. 1. FIG. 1 illustrates a conventional pixel structure of an LCD. As shown in FIG. 1, the pixel structure 10 includes a substrate 12; a thin film transistor (TFT) region 14 and a pixel region 16 defined on the substrate 12. The TFT region 14 includes a TFT, which includes a gate electrode 18, a gate insulating layer 20, a semiconductor layer 22, a heavily doped semiconductor layer 24, a source electrode 26, and a drain electrode 28. The pixel region 16 includes a common electrode 30, a dielectric layer 32, and a pixel electrode 34. The pixel electrode 34 and the drain electrode 28 are electrically connected together, the drain electrode 28 and the common electrode 30 partially overlap, and the overlapping part of the drain electrode 28 and the common electrode 30 forms a storage capacitor Cst.
The storage capacitor Cst of the conventional pixel structure 10 is formed by the overlapping part of two conductive layers including the drain electrode 28 and the common electrode 30. To increase the capacitance, the overlapping area of the drain electrode 28 and the common electrode 30 must increase, and this, however, would reduce the aperture ratio and influence display effect.